This code does not need to have a timer object on the form. Change PAUSE to make the label flash at a different speed
Code:
    Dim dblClock As Double
    Dim dblLastChange As Double
    Const PAUSE = 0.25 ' Flash every 1/4 second
    
    dblClock = Timer
    While Timer < dblClock + 4
        If dblLastChange + PAUSE < Timer Then
            dblLastChange = Timer
            If Label1.BackColor = vbRed Then
                Label1.BackColor = vbWhite
            Else
                Label1.BackColor = vbRed
            End If
        End If
        DoEvents
    Wend